Box construction



June 18, 1935. c. K. ELLSWORTH BOX CONSTRUCTION Filed July 19, 1954 2 Sheets-Sheet l f m w" Y ATTORNEY June 18, 1935. c. K. ELLSWORTH BOX CONSTRUCTION Filed July 19, 1954 2' Sheets-Sheet 2 IIIIIIIIPIIIIII "1,111,111,111

I N VE NTOR. ($5155 KEzMh OEW/ ATTORNEY.

Patented June 18, 1935 UNITED STATES PATENT OFFVIVICE This application is a continuation-in-part of my co-pending application Serial No. 688,964, filed September 11, 1933.

The present invention pertains to a novel box made of material known as single-face corrugated stock. This material consists of a corrugated piece on one surface of which is secured a flat or face piece. The stock may consist of any suitable grade of paper such as chip or jute in the cheaper grades and kraft or sulphite in the better and stronger grades.

Among the objects of the invention is the provision of a box that lends itself to novel and interesting' design treatment and one that has comparatively great strength and rigidity for a given weight of stock.

Heretofore single-face corrugated stock has been used as padding. The essential novelty of the present invention resides in the use of such material in making boxes, cartons and other containers, with the corrugations on the outside of the container. Here the corrugations do not perform their usual functions of "padding and cushioning, but the material treated in this way lends itself to interesting ornamental efl'ects as well as to certain mechanical uses of the corrugations not heretofore realized.

Among these uses is the interlocking engagement between a flap on one of the walls of the box and a tuck folded under from one of the other walls of the box. The flap and tuck are so positioned that the corrugations of one lie parallel to and face those of'the other, whereupon a meshing of the corrugations occurs when the flap is inserted. The total area of a corrugated surface is naturally larger than that of a plane surface within the same confines. Consequently there is a correspondingly greater area of frictional contact between the flap and the tuck, as a result of which the flap is held more securely than if it were flat. Another result of the interlocking engagement of the corrugated surfaces is that it functions as a brace against side play of the flap, the wall carrying the flap, and in fact the box as a whole.

In most boxes formed of a blank of single-face corrugated stock, there is at least one score line or crease transversely of the corrugations. The creasing of the material transversely of the corrugations brings the corrugated sheet into firm contact with the face sheet along "the crease line. Also, the corrugations are somewhat widened where flattened against the'crease line, with the result that the solid thickness of the stock is increased along a substantial part of the crease line length and the box structure is reinforced at the crease where increased strength is needed.

The flattening of the corrugations is gradual,

increasing with the approach to thecrease line. 5

Consequently there is a tapering of the corrugations towards the crease line, producing an interesting'design effect and also reducing the exposure of the corrugations at the most sensitive places, namely the corners or edges.

Finally, single-face corrugated stock is more economical than plain flat stock for a given strength of box. A single-face corrugated piece of given strength .has been found to weigh approximately one-half to one-third less than a plain flat sheet of the same strength. Boxes are specified for strength, which depends on the weight, and are priced according to weight. Consequently the reduction in necessary weight for a given strength, by the use of single-face corrugated stock, is an important economy.

The invention is fully-disclosed by way of example in the following description and in the accompanying drawings in which Figure l is a plan view of the blank, showing the inner surface thereof;

Figure 2 is a top plan view of the box in open condition showing the latches and the overlapping bottom pieces;

Figure 3 is an end view of Figure 2, showing the latch in elevation; W

Figure 4 is a front elevation, partly in section, showing the flaps about to be inserted; Y I

Figure 5 is a perspective view of the box with the cover slightly raised;

Figure 6 is a detail section of the bottom, showing the meshing engagement between certain corrugated parts; 7

Figure 7 is a section on the line 11 of Figure 6; 7 40 Figure 8 is an enlarged section on the line 8-8 ofv Figure fifshowing the flattening of the corrugations by creasing the material with the corrugations outward;

Figure 9 is a perspective view of the box in closed position;

Figure 10 is a detail elevation thereof at one of the corners;

Figure 11 is a section on the line Hll of Figure 10;

I Figure 12 is a cross section of the corrugated stock;

Figure 13 is a crosssection of the stock at a score line; i

of a suitable grade of paper such as chip, jute,

kraft or sulphite. I

Blank I is of substantially rectangular form, in

the present instance, with the exception of a tab that the tab 4 is located atone of the narrower edges of the blank, representing the width, and that the other edges represent the length of the blank. It will be understood, however, that this relation maybe altered in laying out a blank for a box having a top and bottom that are not square. In the present instance, the top and bottom are square, as Will presently be shown.

From the end of the tab 4, two score lines 5 and 6 are drawn lengthwise of the blank and parallel to the longitudinal edges. A score line "I is drawn across the sheet parallel to the edge 8 carrying the tab 4. and'spaced from this edge a distance equal to the length of the tab 4. The lines 5, 8 and I and the edge 8 define a square 9 designed to constitute the top of the box. The blank is cut at In along the line 'I from'the longitudinal edges of the blank as far as the corners of the square 9.

are cut in the blank along this line from the lon-- is located at a distance from theline equal to a side of the square 9. The lines H and I6 form with the lines 5 and 6 another square II equal to the square 9 and constituting the bottom of the box. The blank is again slotted along the line I6 from the outer end thereof inward as far as the corners of the square IT as indicated by the numeral I8. I

Between the line I6 and the remaining short edge I8 of the blank, there'remains a strip equal in width to the, end wall I3; Thelines 5 6 and I 6 define in this strip a rectangle 20 equal tothe rectangle I3 and constituting vthe opposite end wall of the box. Outward of the. lines 5 and 6.

and between the slots. I8 and edge I9 are formed Wings 2| and 2| at the ends of rectangle 20 for a purpose which will presently appear. In cases where the box is so dimensioned that the wings do not meet, there is no latching, and the box is held together by the engagement of the wings with top- 9 and flaps 24, 25. a

The blank is again scored'lengthwise at 22 and 23 between the edge 8 and line I I! a comparatively shortdistance fromthe longitudinal edges of the blank to form a pair of flaps 24 and 25. The lines.

22 and 23 co-operate with the lines 5 and 6 respectively to form a pair of rectangles 26 and 21 constituting opposite side walls of the box. The distance between lines 5 and 22 and between lines 6 and 23 is equal to the distance between lines I and II, as these three distances represent the height or depth of the assembled box.

The wings I4 and 2| are each notched at 28 near one of the outer corners, the notches terminating in slits 29 lying in the prolongation of the score. line 22. Both notches 2B face in the same direction. The distance between each slit 29 and the line 5 is equal to half a side of the square 9 or II.

In like manner, the wings I5 and 2| are notched at 30 near one of the outer corners of each, the notches terminating in slits 3| in the prolongation of the score line 23. The notches 3Q face in the opposite direction of the notches 28. Again, the distance between each slit 3| and the line 6. is equal to half a side of the square 9 or II.

Outward of the lines 5 and 6 and between the slots I2 and I8 there'remain pieces 30 and 3W. In assembling the box, these pieces are folded over on the bottom I'I so that the corrugations of these pieces are outward or exposed. In this position they reinforce the bottom. If desired, these pieces may be cut off on lines parallel to the lines 5 and 6 to such an extentthat their free edges abut each other on the bottom I'I, thereby covering the bottom without overlapping, but if overlapping is objectionable, the excess material is preferably used for internal bracing.

The blank is then creased on lines Hand I6,

bringing the end walls I3 and 20 inplanes per-- pendicular to that of the bottom II. The wings I5 and 2| are now swung inward on the line 6 and are interlocked at their notches 30 and slits 3|. Thus joined, the wings are exactly coextensive with one side of the square because of the relation of dimensions previously described. Similarly, the wings I4 -and2l are turned inward on:

the line 5 and interlocked at the notches 28 and slits 29.

Another crease is now taken along the line I,

bringing the top 9 directly over the bottom II.

The tab 4 is inserted against the inner face of end, wall 20 and along the edge III. The side walls 26 and 21 are now turned downward on the lines 5 and 6, whereby these walls cover the interlocked wings I4 and 2|. remain exposed, and these, after being' fold'edon lines 22 and 23 respectively,'are inserted beneath the wings in the spaces provided by slots I2 and I8, whereby the flaps come into surface engagement withthe folds 3|! and 3|. The blank is laid out for scoring and folding insuch a way that the corrugations run perpendicu v lar to the line 5 on which the folds 3|] and 3| are creased. I Where the corrugations run in this manner from one crease line to the next, they serve as an effective brace for the wall on'which they lie. j 1

Also, throughout the creasing operations,the

corrugations are caused to remain on the outside;

Therefore, in inserting the flaps 2 4 and 25, the

corrugated surface of each engages the corrugated surface. of the corresponding fold 3|! or 3|, with the corrugations on the folds parallel to those on the flaps, so that they mesh or interlock as shown more clearly on Figures 6 and 7. This form of engagement results in a large total area of frictional surface contact relatively to the over-all area of the pieces. with more than usual firmness in the inserted position, and this is true although there may be more or less outward bulge of the bottom II along Only the flaps 24 and 25 now.

The flaps are, therefore, held;

the lines and 6, as the extent of the bulge diminishes in receding from the edges.

Further, the meshing of the corrugations resistsside play of the flaps 24 and 25, thereby retaining also the side walls 26 and 21 and maintaining the; desired shape of the whole box. In this connection it is to be noted that the ends of the flaps 24 and 25 alone are not sufficient to brace the box, first because they are shortened by rounding the corners of the flaps at 32 to facilitats insertion, and second because the stock. is weak at the edges and breaks down.

Another property of the interlocking engagement of the corrugations is the sealing effect produced thereby. The sealing effect, which is pro portional to the increased area of contact as already set forth, is usual in insulating the contents of the box from outside air and heat, especially when the box contains unwrapped food, such as cookies, or bottles of a chilled beverage.

Another important feature of the invention is the formation that/occurs by the distortion of the corrugations where the blank is creased transversely of the corrugations, with the corrugations on the outside, as shown in Figures 8 to 15. This formation is best illustrated in Figures 14 and 15, showing the formation on a magnified scale. The corrugated sheet 43 is secured to the face sheet 4! along parallel bands 42'which constitute the troughs between the corrugations 43 where the sheet All is spaced from the sheet 4 I. On forming a crease in the manner described along a score line 7 shown in Figure 12, the sheet 49 is placed under tension in the direction of the corrugations, flattening the corrugations into contact with the crease line along areas of contact at least as wide as the spaces between the adhesion bands 42. Thus, the solid, uninterrupted thickness of the stock is increased by the thickness of the sheet 40 not only at the bands, but also in the spaces between the bands, thereby reinforcing the box where added strength is needed, namely at the crease. In fact, the corrugations in flattening overlap the secured areas to form ribs 44 of still greater thickness and strength across the crease at intervals.

Considering the distortion of the corrugations in the lengthwise direction it will be seen that the flattening is gradual, reaching its maximum at the crease line 45. In other words, there is a taper 46 of the material on adjacent perpendicular walls of the box and towards the crease line, as may be seen in Figures and 11. This formation reduces the protrusion and exposure of the corrugations at the creases where the wear on the outer surface of the box is the greatest, and as a result of this formation the sheet 40 remains intact at the crease notwithstanding severe wear in this area.

The invention is not limited to paper stock, as other fabric and flexible materials may be corrugated and used in the manner described. Although a specific embodiment of the invention has been illustrated and described, it will be understood that various alterations in the details of construction may be made without departing from the scope of the invention, as indicated by the appended claims.

What I claim is:

1. In a box, a sheet of single-face corrugated stock creased to present the corrugations outward, a tuck under one of the sides of the box with its corrugated side facing inward of the box, a flap formed on another wall of the box and positioned to be inserted in surface engagement with said tuck and with its corrugations parallel to and in mesh with" those of the tuck.

2. In a box, a sheet of single-face corrugated stock creased to present the corrugations outward, a tuck under one of the sides of the box with its corrugated side facing inward of the box, a flap formed on another wall ofthe box and p0- sitioned to be inserted in surface engagement with said tuck and with its corrugations parallel to and in mesh with those of the tuck, and means for maintaining said tuck and flap in surface engagernent with each other.

3. In a box, a sheet of single-face corrugated stock creased to present the corrugations outward, a tuck under one of the sides of the box with its corrugated side facing inward of the box, a flap formed on another wall of the box and positioned to b inserted in surface engagement with said tuck and with its corrugations parallel to and in mesh with those of the tuck, and a leaf integral with said sheet and swingable on an axis angular to that of the tuck, the flap being insertable between said leaf and said flap, whereby the leaf tends to maintain the tuck and flap in surface engagement with each other.

4. A box comprising a blank having two score lines in one direction and three score lines in the perpendicular direction, thereby forming four rectangles between the first two lines, two alternate rectangles constituting the top and bottom respectively and the intervening rectangles constituting end walls, the blank being slit outward from the first two lines along the second named three score lines, thereby forming wings at the ends of the end walls and lateral pieces at the ends of the top and bottom, those at the bottom being folded inwardly and lying flat on the bottom, and those at the top constituting side walls,

means for interlocking said wings along the side walls, and flaps formed on said side walls respectively on lines parallel to the first two score lines and inserted beneath said wings and into surface contact with the lateral pieces overlying the bottom.

5. A box comprising a blank having two score lines in one direction and three score lines in the perpendicular direction, thereby forming four rectangles between the first two lines, two alternate rectangles constituting the top and bottom respectively and the intervening rectangles constituting end walls, the blank being slit outward from the first two lines along the second named three score lines, thereby forming wings at the ends of the end walls and lateral pieces at the ends of the top and bottom, those at the bottom being folded inwardly and lying flat on the bottom and those at the top constituting side walls, means for interlocking said wings along the side walls, and flaps formed on said side walls respectively on lines parallel to the first two score lines and inserted beneath said wings and into surface contact with the lateral pieces overlying the bottom, the wings being enclosed by said side walls.

6. A box comprising a blank having two score. lines in one direction and three score lines in the perpendicular direction, thereby forming four rectangles between the first two lines, two alternate rectangles constituting the top and bottom respectively and the intervening rectangles constituting end walls, the blank being slit outward from the first two lines along the second named three score lines, thereby forming wings at the ends of the end walls and lateral pieces at the ends of the top and bottom, those at the bottom being 7 folded inwardly and lying flat on the bottom and those at the top constituting side walls, means for interlocking said wings along the side walls, and flaps formed on said side walls respectively on lines parallel to the first two score lines and inserted beneath said wings and into surfacecontact with the lateral pieces overlying the bottom, said blanks being corrugated on the outside, the corrugations running transversely of the first two score lines, the corrugations on the flaps being adapted to mesh and interlock with those on the lateral pieces overlying the bottom.

7. A box comprising a blank having two score lines in one direction and three score lines in the perpendicular direction, thereby forming .four rectangles between the'first two lines, two al ternate rectangles constituting the top and bottomrespectively and the intervening rectangles constituting end Walls, the blank being slit outward from the first two lines along the second named three score lines, thereby forming wings at the ends of the end Walls and lateral pieces at the ends of the topand bottom, those at the bottom being folded inwardly and lying flat on the bottom and those at the top constituting side walls, means for interlocking said. wings along the side walls, flaps formed on said side walls respectively on lines parallel to the first two score lines and inserted beneath said wings and into surface contact with the lateral pieces overlying the bottom, a corrugated sheet covering the outer surface of the blank or box, the corrugations running transversely of the first two score lines, the corrugations on the flaps being adapted to mesh and interlock with those on the lateral pieces overlying the bottom.

8. A box made of single-face corrugated stock, said stock consisting of a flat sheet and a corrugated sheet secured thereto along spaced bands at the bases of the corrugations, the crests of the corrugations being spacedv from said flat sheet, said box having at least one crease transversely of the corrugations, the corrugations being exposed on the outside of the angle thus formed, the crests of the corrugations being flattened into firm engagement with the flat sheet at said crease and between said bands.

9. A box made of single-face corrugated stock, said stock consisting of a'flat sheet and a corrugated sheet secured thereto along spaced bands at the bases ofthe'corrugations, the crests of the corregations being spaced from saidfiat sheet, said box having at least one crease transversely of the corrugations, the corrugations being exposed on the outside of the angle thus formed, the crests of the corrugations being flattened into firm engagement with the flat sheet at said crease and between said bands, theflattened corrugations overlapping said bands to form ribs.

10. A box made of single-face corrugated stock, said stock consisting of a flat sheet and a corrugated sheet secured thereto along spaced bands at the bases of the corrugations, said sheet being creased transversely of the corrugations, the corrugations gradually diminishing in height towards the crease from points spaced from said crease, and being flattened into engagement with the flat sheet at the crease.

CHARLES K. ELLS WORTH. 

